等高布局

<div class="parent">
    <div class="left">left</div>
    <div class="right">rkerjerje erjerkerjekrjerlf ererejrjerjerje</div>
</div>

.parent{
   display:table; 
}

.left,.right{
   width:300px;
   display:table-cell;/*表格的单元格默认是等高的*/

} 
.left{ background-color:#c9394a; } 
.right{ background-color:#ccc; }

.parent{
  overflow:hidden;
}
.left,.right{
   width:300px;
   float:left;

   padding-bottom:9999px;
   margin-bottom:-9999px;
} 
.left{ 
   background-color:#c9394a; 
} 
.right{ 
   background-color:#ccc; 
}